feat: scope Saved Queries panel to active connection + clean up on delete

Two changes that close the "everything lives in one global pool" gap.

UI: Saved Queries sidebar now defaults to "This connection" and lists
only entries with `connection_id == activeConnectionId` plus unattached
entries (legacy global saves before F2). A small toggle ("All") above
the search box brings the previous behavior back when copying queries
between databases. Each row in "All" mode shows a tag with the source
connection's name; legacy global entries show "unattached".

Backend: delete_connection now best-effort cleans persisted state for
that connection — removes `memory/<id>.md` (delete_memory_core in
memory.rs) and drops every entry in saved_queries.json with the
matching `connection_id` (delete_by_connection_core in
saved_queries.rs). Entries with `connection_id == None` are deliberately
preserved. Cleanup errors are logged but don't block the deletion since
connections.json is the source of truth.

Memory was already per-connection (F1); query history already filters
by connection. This commit makes saved queries behave the same and
stops orphan files from accumulating.

src/components/saved-queries/SavedQueriesPanel.tsx

@@ -1,19 +1,41 @@
-import { useState } from "react";
+import { useMemo, useState } from "react";
 import { useSavedQueries, useDeleteSavedQuery } from "@/hooks/use-saved-queries";
 import { useAppStore } from "@/stores/app-store";
 import { Input } from "@/components/ui/input";
 import { Button } from "@/components/ui/button";
 import { Search, Trash2, Bookmark } from "lucide-react";
-import type { Tab } from "@/types";
+import type { SavedQuery, Tab } from "@/types";
+
+type Scope = "active" | "all";
 
 export function SavedQueriesPanel() {
   const [search, setSearch] = useState("");
-  const { activeConnectionId, currentDatabase, addTab } = useAppStore();
+  const [scope, setScope] = useState<Scope>("active");
+
+  const { activeConnectionId, currentDatabase, addTab, connections } =
+    useAppStore();
   const { data: queries } = useSavedQueries(search || undefined);
   const deleteMutation = useDeleteSavedQuery();
 
-  const handleOpen = (sql: string, connectionId?: string) => {
-    const cid = activeConnectionId ?? connectionId ?? "";
+  // Effective scope: if no connection is active, "active" has nothing to filter
+  // against, so we silently broaden to all.
+  const effectiveScope: Scope = activeConnectionId ? scope : "all";
+
+  const visible = useMemo(() => {
+    if (!queries) return [];
+    if (effectiveScope === "all") return queries;
+    return queries.filter(
+      (q) => !q.connection_id || q.connection_id === activeConnectionId
+    );
+  }, [queries, effectiveScope, activeConnectionId]);
+
+  const connectionName = (id: string | undefined): string | undefined => {
+    if (!id) return undefined;
+    return connections.find((c) => c.id === id)?.name ?? id.slice(0, 8);
+  };
+
+  const handleOpen = (sql: string, queryConnectionId?: string) => {
+    const cid = activeConnectionId ?? queryConnectionId ?? "";
     if (!cid) return;
     const tab: Tab = {
       id: crypto.randomUUID(),
@@ -28,7 +50,7 @@ export function SavedQueriesPanel() {
 
   return (
     <div className="flex h-full flex-col">
-      <div className="flex items-center gap-1 p-2">
+      <div className="flex flex-col gap-1.5 p-2">
         <div className="relative flex-1">
           <Search className="absolute left-2 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground" />
           <Input
@@ -38,45 +60,121 @@ export function SavedQueriesPanel() {
             onChange={(e) => setSearch(e.target.value)}
           />
         </div>
+        {activeConnectionId && (
+          <div className="flex gap-1">
+            <ScopeButton
+              active={scope === "active"}
+              onClick={() => setScope("active")}
+            >
+              This connection
+            </ScopeButton>
+            <ScopeButton
+              active={scope === "all"}
+              onClick={() => setScope("all")}
+            >
+              All
+            </ScopeButton>
+          </div>
+        )}
       </div>
       <div className="min-h-0 flex-1 overflow-y-auto">
-        {queries?.map((query) => (
-          <div
+        {visible.map((query) => (
+          <QueryRow
             key={query.id}
-            className="group flex w-full flex-col gap-0.5 border-b px-3 py-2 text-left text-xs hover:bg-accent cursor-pointer"
-            onDoubleClick={() => handleOpen(query.sql, query.connection_id)}
-          >
-            <div className="flex items-center gap-1.5">
-              <Bookmark className="h-3 w-3 shrink-0 text-blue-400" />
-              <span className="truncate font-medium text-foreground">
-                {query.name}
-              </span>
-              <Button
-                variant="ghost"
-                size="icon"
-                className="ml-auto h-5 w-5 shrink-0 opacity-0 group-hover:opacity-100 text-destructive hover:text-destructive"
-                onClick={(e) => {
-                  e.stopPropagation();
-                  deleteMutation.mutate(query.id);
-                }}
-              >
-                <Trash2 className="h-3 w-3" />
-              </Button>
-            </div>
-            <span className="truncate font-mono text-muted-foreground">
-              {query.sql.length > 80 ? query.sql.slice(0, 80) + "..." : query.sql}
-            </span>
-            <span className="text-muted-foreground">
-              {new Date(query.created_at).toLocaleDateString()}
-            </span>
-          </div>
+            query={query}
+            showConnectionTag={effectiveScope === "all"}
+            connectionLabel={connectionName(query.connection_id)}
+            onOpen={() => handleOpen(query.sql, query.connection_id)}
+            onDelete={() => deleteMutation.mutate(query.id)}
+          />
         ))}
-        {(!queries || queries.length === 0) && (
+        {visible.length === 0 && (
           <div className="py-8 text-center text-xs text-muted-foreground">
-            No saved queries
+            {effectiveScope === "active"
+              ? "No saved queries for this connection"
+              : "No saved queries"}
           </div>
         )}
       </div>
     </div>
   );
 }
+
+function ScopeButton({
+  active,
+  onClick,
+  children,
+}: {
+  active: boolean;
+  onClick: () => void;
+  children: React.ReactNode;
+}) {
+  return (
+    <button
+      onClick={onClick}
+      className={`h-6 rounded px-2 text-[11px] transition-colors ${
+        active
+          ? "bg-accent text-foreground"
+          : "text-muted-foreground hover:text-foreground hover:bg-accent/50"
+      }`}
+    >
+      {children}
+    </button>
+  );
+}
+
+function QueryRow({
+  query,
+  showConnectionTag,
+  connectionLabel,
+  onOpen,
+  onDelete,
+}: {
+  query: SavedQuery;
+  showConnectionTag: boolean;
+  connectionLabel?: string;
+  onOpen: () => void;
+  onDelete: () => void;
+}) {
+  const tag = !query.connection_id
+    ? "unattached"
+    : showConnectionTag
+      ? connectionLabel
+      : null;
+
+  return (
+    <div
+      className="group flex w-full flex-col gap-0.5 border-b px-3 py-2 text-left text-xs hover:bg-accent cursor-pointer"
+      onDoubleClick={onOpen}
+    >
+      <div className="flex items-center gap-1.5">
+        <Bookmark className="h-3 w-3 shrink-0 text-blue-400" />
+        <span className="truncate font-medium text-foreground">
+          {query.name}
+        </span>
+        {tag && (
+          <span className="shrink-0 rounded bg-muted/40 px-1 py-px text-[9px] uppercase tracking-wide text-muted-foreground">
+            {tag}
+          </span>
+        )}
+        <Button
+          variant="ghost"
+          size="icon"
+          className="ml-auto h-5 w-5 shrink-0 opacity-0 group-hover:opacity-100 text-destructive hover:text-destructive"
+          onClick={(e) => {
+            e.stopPropagation();
+            onDelete();
+          }}
+        >
+          <Trash2 className="h-3 w-3" />
+        </Button>
+      </div>
+      <span className="truncate font-mono text-muted-foreground">
+        {query.sql.length > 80 ? query.sql.slice(0, 80) + "..." : query.sql}
+      </span>
+      <span className="text-muted-foreground">
+        {new Date(query.created_at).toLocaleDateString()}
+      </span>
+    </div>
+  );
+}